Mastitis Pathogen Factsheet #1 University of Minnesota College of Veterinary Medicine

E. coli & Coliform Mastitis

Escherichia coli is a Gram-negative bacteria, contaminated bedding, and poor hygiene practices frequently grouped with other coliform bacteria of the during milking are also risk factors. family Enterobacteraciae. Other coliforms include Klebsiella and Enterobacter species. Treatment Several studies have found that undifferentiated cases Source / Transmission of mild or moderate coliform mastitis have a high rate E. coli and other coliform bacteria are found in high of spontaneous cure3,4, meaning that the cow’s concentration in organic matter, such as bedding and immune system is able to clear the infection without manure. Udders become infected with coliform antimicrobial therapy. Based on this fact, some dairy bacteria through contact with organic matter in the producers choose not to use intramammary antibiotics environment or during milking. for mastitis cases that are caused by Gram-negative bacteria. However, recent work suggests that mastitis Infection cases caused by Klebsiella spp. have a lower Once inside the udder, E. coli multiply rapidly, spontaneous cure rate and therefore may benefit from 5 causing an influx of inflammatory cells. As intramammary therapy. In addition, some proportion neutrophils ingest and kill bacteria, endotoxin (LPS) is of coliforms, including E. coli, may become chronic 6 released and along with other inflammatory mediators or recurrent infections. Cows with severe cases of causes severe local inflammation. This inflammatory coliform mastitis should be treated with systemic and response is characterized by increased vascular supportive therapies, including fluids, anti- permeability, changes in milk composition and inflammatories and systemic antimicrobial therapy. damage to the mammary epithelial cells – all of which may result in the characteristic watery or serous milk Control secretion. Maintaining a clean, dry environment for cows is important to reduce exposure of the teat end to dirt Because of the robust immune response, the majority and manure. This includes frequent scraping of alleys of clinical coliform cases are mild and short-duration, and holding pens, and keeping stalls or areas where and many infections may go undetected. However, cows lie down clean and well-bedded. Pre- and post- clinical symptoms are a result of the inflammatory milking teat disinfection and good milking practices process and frequently include a hot, hard or swollen are also important. Coliform mastitis vaccines have quarter. Coliform bacteria may be implicated in 50 – proven effective at reducing the severity of clinical 70% of severe mastitis cases.1 In these cases, systemic cases and are recommended in most herds. illness is caused by endotoxin release into the bloodstream, and the affected cow may exhibit an References 1 Erskine et al. 2002. Efficacy of Systemic Ceftiofur as a Therapy for Severe initial high fever followed by subnormal temperature, Clinical Mastitis in Dairy Cattle. J. Dairy Sci. 85(10):2571-2575 depression, anorexia, rumen stasis, diarrhea, and 2 Wenz et al. 2004. Bacteremia associated with naturally occurring acute coliform mastitis in dairy cows. J Am Vet Med Assoc. 219(7):976-981 potentially progressing to recumbancy and death. In 3 Morin et al. 1998. Comparison of antibiotic administration in conjunction with one study of acute coliform mastitis, bacteria were supportive measures versus supportive measures alone for treatment of dairy 2 cows with clinical mastitis. J Am Vet Med Assoc. 213(5):676–84. isolated from the bloodstream in 32% of cases. 4 Wilson et al. 1999. Comparison of seven antibiotic treatments with no treatment for bacteriological efficacy against bovine mastitis pathogens. J. Dairy Sci. 82:1664-1670. Risk Factors 5 Schukken et al. 2011. Randomized clinical trial to evaluate the efficacy of a 5- New infections can occur throughout lactation, day ceftiofur hydrochloride intramammary treatment on nonsevere gram-negative clinical mastitis. J. Dairy Sci. 94:6203–6215 however cows most at risk for coliform mastitis are 6 Schukken et al. 2004. Chronic and Recurrent Coliforms: Implication for those early in lactation and immediately after dry-off. Lactation Therapy. NMC Annual Meeting Proceedings, pp35-40 Poor environmental hygiene, such as manure

Updated February 2014